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authorLen Brown <len.brown@intel.com>2015-10-20 05:37:40 +0300
committerLen Brown <len.brown@intel.com>2015-10-20 05:50:01 +0300
commit21ed5574d1622118b49b0c6342acc8d27d0799be (patch)
tree820cff28eaa5434ab74155d2a5b18cf6b8f11699 /tools/power
parent7379047d5585187d1288486d4627873170d0005a (diff)
downloadlinux-21ed5574d1622118b49b0c6342acc8d27d0799be.tar.xz
tools/power turbostat: simplify Bzy_MHz calculation
Bzy_MHz = TSC_delta*tsc_tweak/APERF_delta/MPERF_delta/measurement_interval becomes Bzy_MHz = base_mhz/APERF_delta/MPERF_delta on systems which support MSR_NHM_PLATFORM_INFO. base_mhz is calculated directly from the base_ratio reported in MSR_NHM_PLATFORM_INFO * bclk, and bclk is discovered via MSR or cpuid. This reduces the dependency of Bzy_MHz calculation on the TSC. Previously, there were 4 TSC readings required in each caculation, the raw TSC delta combined with the measurement_interval. This also removes the "tsc_tweak" correction factor used when TSC runs on a different base clock from the CPU's bclk. After this change, tsc_tweak is used only for %Busy. The end-result should be a Bzy_MHz result slightly less prone to jitter. Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'tools/power')
-rw-r--r--tools/power/x86/turbostat/turbostat.c28
1 files changed, 17 insertions, 11 deletions
diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index bde0ef1a63df..84ec4e459975 100644
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -75,6 +75,7 @@ unsigned int aperf_mperf_multiplier = 1;
int do_smi;
double bclk;
double base_hz;
+unsigned int has_base_hz;
double tsc_tweak = 1.0;
unsigned int show_pkg;
unsigned int show_core;
@@ -96,6 +97,7 @@ unsigned int do_ring_perf_limit_reasons;
unsigned int crystal_hz;
unsigned long long tsc_hz;
int base_cpu;
+double discover_bclk(unsigned int family, unsigned int model);
#define RAPL_PKG (1 << 0)
/* 0x610 MSR_PKG_POWER_LIMIT */
@@ -511,9 +513,13 @@ int format_counters(struct thread_data *t, struct core_data *c,
}
/* Bzy_MHz */
- if (has_aperf)
- outp += sprintf(outp, "%8.0f",
- 1.0 * t->tsc * tsc_tweak / units * t->aperf / t->mperf / interval_float);
+ if (has_aperf) {
+ if (has_base_hz)
+ outp += sprintf(outp, "%8.0f", base_hz / units * t->aperf / t->mperf);
+ else
+ outp += sprintf(outp, "%8.0f",
+ 1.0 * t->tsc / units * t->aperf / t->mperf / interval_float);
+ }
/* TSC_MHz */
outp += sprintf(outp, "%8.0f", 1.0 * t->tsc/units/interval_float);
@@ -1158,12 +1164,6 @@ int phi_pkg_cstate_limits[16] = {PCL__0, PCL__2, PCL_6N, PCL_6R, PCLRSV, PCLRSV,
static void
calculate_tsc_tweak()
{
- unsigned long long msr;
- unsigned int base_ratio;
-
- get_msr(base_cpu, MSR_NHM_PLATFORM_INFO, &msr);
- base_ratio = (msr >> 8) & 0xFF;
- base_hz = base_ratio * bclk * 1000000;
tsc_tweak = base_hz / tsc_hz;
}
@@ -1821,6 +1821,7 @@ void check_permissions()
int probe_nhm_msrs(unsigned int family, unsigned int model)
{
unsigned long long msr;
+ unsigned int base_ratio;
int *pkg_cstate_limits;
if (!genuine_intel)
@@ -1829,6 +1830,8 @@ int probe_nhm_msrs(unsigned int family, unsigned int model)
if (family != 6)
return 0;
+ bclk = discover_bclk(family, model);
+
switch (model) {
case 0x1A: /* Core i7, Xeon 5500 series - Bloomfield, Gainstown NHM-EP */
case 0x1E: /* Core i7 and i5 Processor - Clarksfield, Lynnfield, Jasper Forest */
@@ -1871,9 +1874,13 @@ int probe_nhm_msrs(unsigned int family, unsigned int model)
return 0;
}
get_msr(base_cpu, MSR_NHM_SNB_PKG_CST_CFG_CTL, &msr);
-
pkg_cstate_limit = pkg_cstate_limits[msr & 0xF];
+ get_msr(base_cpu, MSR_NHM_PLATFORM_INFO, &msr);
+ base_ratio = (msr >> 8) & 0xFF;
+
+ base_hz = base_ratio * bclk * 1000000;
+ has_base_hz = 1;
return 1;
}
int has_nhm_turbo_ratio_limit(unsigned int family, unsigned int model)
@@ -2780,7 +2787,6 @@ void process_cpuid()
do_skl_residency = has_skl_msrs(family, model);
do_slm_cstates = is_slm(family, model);
do_knl_cstates = is_knl(family, model);
- bclk = discover_bclk(family, model);
rapl_probe(family, model);
perf_limit_reasons_probe(family, model);